File:A manual of practical medical electricity - the Röntgen rays and Finsen light (1902) (14597015680).jpg

Identifier: manualofpractica00turn (find matches)
Title: A manual of practical medical electricity : the Röntgen rays and Finsen light
Year: 1902 (1900s)
Authors: Turner, Dawson
Subjects: X-Rays Electrophysiology Electrosurgery Electric Stimulation Therapy Electrotherapeutics X-rays Electrophysiology Electrosurgery
Publisher: New York : William Wood & Company
Contributing Library: Francis A. Countway Library of Medicine
Digitizing Sponsor: Open Knowledge Commons and Harvard Medical School

View Book Page: Book Viewer
About This Book: Catalog Entry
View All Images: All Images From Book
Click here to view book online to see this illustration in context in a browseable online version of this book.

Text Appearing Before Image:
e taken to keep it quite dry (purerock-salt does not deliquesce), for a film of moisture uponit, owing to the electrical conductivity of brine, makes itquite opaque to the radiation, and also destroys its polish.It may be cleaned by a soft rag moistened with absolutealcohol. Mode of Employment of Ultra-Violet Rays. In the original method employed by Finsen with thearc light (Fig. 168), four telescopic tubes were arrangedat an angle of 45° from the horizontal round a large arclamp which required current at the rate of 60 amperes.The function of these tubes was to concentrate the violetand ultra-violet rays and to remove the heat rays. Therays were concentrated by quartz lenses, between whichwas a column of running water to absorb the rays of heat.In addition, a hollow compressor of quartz, also containingrunning water, was needed to render the skin anemic andcom.pletely cool the light. It is easy to see that by the time the light has traversed A Manual of Practical Medical Electricity
Text Appearing After Image:
Fig. )68.—Finskn Arc Light. Ultra-Violet Rays 369 the considerable distance, and the various cooling andconcentrating media between the arc light and the patient,there will not be much of the ultra-violet light left; forboth the quartz and the water absorb a certain percentageof it, and some will be lost on entering and leaving everyfresh surface. Further, the expense of the installationis very great (£100 to £200) and its upkeep considerable ;but the greatest drawback of all is the time occupied mthe treatment. A lengthy exposure of an hour and aquarter is found necessary, and this has to be repeateddaily for months. A large amount of power—somethinglike eight horse-power at 100 volts—is being consumedto produce a small and tardy effect in four patients. Thiswould be all very well if there was no other way of pro-ducing the effect, but, fortunately, owing to recent improve-ments, there is. The inefficiency of the original methoddepends mainly on the great distance the lamp is

Note About Images